feat: add CachedService with cached collections and delta

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

tests/php/Support/FakeMailboxStore.php

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace KTXT\ProviderImap\Tests\Support;
+
+use KTXM\ProviderImap\Providers\CollectionResource;
+use KTXM\ProviderImap\Stores\MailboxStore;
+
+/**
+ * In-memory MailboxStore: documents, state, change sequence and a single lock.
+ */
+final class FakeMailboxStore extends MailboxStore
+{
+    /** @var array<string, array> */
+    public array $documents = [];
+    public ?string $lockOwner = null;
+    /** Fixed time for listedAt; null = now */
+    public ?int $clock = null;
+
+    public function upsert(string $tenantId, string $serviceId, CollectionResource $collection): void
+    {
+        $name = (string) $collection->identifier();
+        $this->documents[$name] = [
+            ...($this->documents[$name] ?? self::STATE_DEFAULTS),
+            ...$collection->toCacheMeta(),
+            'listedAt' => $this->clock ?? time(),
+        ];
+    }
+
+    public function fetch(string $serviceId, string $name): ?array
+    {
+        return $this->documents[$name] ?? null;
+    }
+
+    public function list(string $serviceId): array
+    {
+        return $this->documents;
+    }
+
+    public function updateState(string $serviceId, string $name, array $state): void
+    {
+        $this->documents[$name] = array_replace($this->documents[$name], array_intersect_key($state, self::STATE_DEFAULTS));
+    }
+
+    public function acquireLock(string $serviceId, string $name, string $owner, int $ttl): bool
+    {
+        if ($this->lockOwner !== null && $this->lockOwner !== $owner) {
+            return false;
+        }
+        $this->lockOwner = $owner;
+        return true;
+    }
+
+    public function releaseLock(string $serviceId, string $name, string $owner): void
+    {
+        if ($this->lockOwner === $owner) {
+            $this->lockOwner = null;
+        }
+    }
+
+    public function reserveSequence(string $serviceId, string $name, int $count = 1): int
+    {
+        $this->documents[$name]['changeSeq'] += $count;
+        return $this->documents[$name]['changeSeq'] - $count + 1;
+    }
+
+    public function state(string $serviceId, string $name): array
+    {
+        return array_replace(self::STATE_DEFAULTS, array_intersect_key($this->documents[$name] ?? [], self::STATE_DEFAULTS));
+    }
+
+    public function listedAt(string $serviceId): ?int
+    {
+        $times = array_filter(array_column($this->documents, 'listedAt'));
+        return $times === [] ? null : max($times);
+    }
+
+    public function delete(string $serviceId, string $name): void
+    {
+        unset($this->documents[$name]);
+    }
+}